Bioethanol Technology Development in the United States

Bioethanol--ethanol produced from lignocellulosic biomass such as agricultural and forestry residues, municipal solid waste, and woody and herbaceous energy cropss--could become a domestically abundant transportation fuel, thus reducing petroleum imports. Ethanol use also improves air quality when blended directly with gasoline, converted to ethyl tertiary butyl ether, or used as neat or purefuel. Bioethanol reduces accumulation of carbon dioxide by 90% or more compared to reformulated gasoline. Significant advances have been made in the technology for enzymatically hydrolyzing cellulose to glucose for fermentation to ethanol, with the projected cost of producing bioethanol dropping from about $1.22/liter (4.63/gallon) in 1980 to only $0.32/liter (1.22/gallon) now, a levelcompetitive for use as a direct gasoline-blending agent. Opportunities exist to further decrease the cost to $0.18 liter ($0.67/gallon) or less to make bioethanol competitive with gasoline as a pure fuel, and recent genetic engineering and pretreatment breakthroughs are major steps toward that goal. Pilot plant work with industiral partners is in progress to provide data needed to commercializecurrent technology and to provide information vital to reducing the cost of bioethanol production further.